98 Windstar Engine Problems...Please Help

I have a 98 wind star and earlier today while driving down the highway the tach went to 0, soon followed by the speedo going to 0, then the radio went crazy switching from front to rear on its own for the speakeres. Then I lost engine power and was sitting on the side of the road.
I tried to start it back up and it acted like the battery was dead. I had a friend come jump start it and started driving home, then after about 3 miles it did the same thing again. This time a wrecker is bringing it home.
Any ideas? Oh... the check engine light came on and I had my OBDII scanner with me I got a PO 401 and PO 402. EGR insufficient flow and excessive flow. That is puzzling to me, how can it be both?
Any way any help you guys can offer will be greatly appreciated. The dang wrecker is costing me a fortune and I cant afford a mechanic to fix it. So Im on my own here guys...

Do you have a wiring diagram for the vehicle? It sounds like you're going to need one.

Just a guess but is it possible that there is some EGR flow but not enough when the PCM commands it on but too much when it is commanded off. Since it sounds like you have an electrical issue perhaps the feedback indicates parftial EGR flow.

Did the CEl come on at the same time you had the problems or some time afterwards?

Your dash and stereo problems seem to be from a common electrical issue. Perhaps a bad alternator since the battery seemed to be drained.

I agree with DRW1000. Check the output of the alt. and the condition of the bat.

Regards

Dan

I thought I should clarify what I meant in regards to the 2 EGR codes since it looked confusing when I read my earlier post the next morning.

Imagine as an example that your EGR is stuck partially open for whatever reason. When the PCM commands the EGR open a certain amount of Exhaust gas will flow.
The DPFE will report a lower amount than what should be flowing (due to the partial open stuck condition) and will flag a low EGR flow condition. When the
PCM commands the EGR to be closed the opposite will happen. There will be flow and the DPFE will report it and the PCM will now consider there to be
an excessive flow condition.

This is one scenario where you could get both codes. There are also electrical conditions that can cause these two codes or a faulty DPFE. The DPFE is a common
failure prone item and it could fail in such a way that sends a constantly partial open signal.

Since you seem to be having electrical issues I would not rule out an electrical problem affecting the DPFE readings either.

That's a good analysis of a double EGR flow code. Since the ECU uses pressure differential sensor change to measure EGR "flow", if the EGR were alreay leaking due to partial blockage, the sensor change may not satisfy the ECU's expectaions, while the "steady state" pressure differential may be in excess of the threshold for maximum flow. Pulling the digital EGR and cleaning it is easy enough.

The fact that everything went dead, however, points to a larger problem, possibly related, or possibly in addition to the EGR problem.

If you needed a JUMP start....then any codes you got.....are "suspect" as when the voltage gets low....who knows what is going to happen.
You need to verify that you have a good battery, alternator, and fuse "T" in the engine compartment "power distribution box".
If the battery is weak, it can cause the alternator to fail.......and fuse "T" is required to be good in order for the alternator to work.

THEN....once you KNOW that your battery and alternator are in good shape.....if you get codes for the EGR....
1. The DPFE is a known item to fail.....relatively easy to replace.
2. The EGR Ports in the lower intake manifold clog up over time.
I have pictures posted, link in my "signature".
You have to remove the upper intake manifold to get to them....then they are easy to clean. Dirt is pretty much always right at the top of the port.....

This whole thing started out with what sounded like an electrical problem or a low battery that the computers onboard don't like.

One thing that I have found over the years is that corrosion on the battery terminals between the connecting wiring terminals will insulate them and cut off the flow those electrons from passing through that connection. The battery cannot supply the system and the alternator cannot charge the battery.

I pull the connector terminals off of the battery once a year here in the north latitudes and every six months in the warmer parts of the world where temperatures and humidity are higher most of the year.

Clean both of the terminals of the battery with the wire brush and or fine sand paper and also the wire terminals that attach to the battery. I clean the wire terminals as best as I can and then use warm or hot water and mix in soda (from the kitchen) to produce soda solution to neutralize any acid that is not where it supposed to be. A couple of table spoons full for a cup of hot water is plenty. I dunk the wire terminals into this solution and continue to clean until all of the green color is gone and then dry them with paper towels. That green stuff is acid and your battery is full of it and some of it goes into a gas and condenses on the terminals and anywhere else it can find, especially in hot humid climates. Do not get the soda solution into the battery. It neturalizes the acid. I use a paper towel and moisten it with some of the soda solution and wipe the top of the battery and etc.

One other thing that I have found is that a loose battery connector can destroy the diodes in the alternater rectifier. If you wiggle a loose battery terminal when it is under load, you will hear it snapping and sparking. Those are momentary interruptions in the flow of current and those electrons have mass and want to continue to keep going and do arch over but they build up a highter voltage than the rating on the diodes in your alternator and burn them out. Driving down the road with a loose battery terminal especially a bumpy road will sure do a number on your alternater.

I would clean and tighten the battery connections and put a light coating of grease on the outside of those terminals after everything is connected. Grease is an insulator, so don't get it into the battery connection.

If you can, check and fill your battery levels with distilled water to the proper levels. Never put water into a battery and let it set. The battery will go dead. Start up the car and charge it for a few minutes after you add water. You can sort of check your alternator by measuring the voltage on your battery with the engine running. It should be something near 13.8+ volts. That means that it is 1.8+ volts above the voltage of your battery and it is charging your battery if your battery is able to accept a charge.

Good luck.

Jim